When using standard Inertial Navigation Systems (INS), the issue of drift can be prevalent to the extent that it can be a problem for normal usage. Updated INS positions are calculated with respect to a previously calculated position, and thus errors in either sensor data or position calculations can be magnified over successive iterations. In some cases, the INS position can be periodically corrected by input from some other type of navigation system, such as global positioning systems (GPS). However, input from other navigations systems is not always available or accurate enough for some systems.